The University of Chicago Medical Scientist Training Program (MSTP) submits this renewal application to the National Institutes of Health (NIH) to continue and expand into this century its training of outstanding leaders in the biomedical field. We request funding for 42 MSTP positions, an increase of 2 over the current recommended level of 40. At the requested level of support, NIH funding will cover approximately 20% of the program's costs, the rest being provided by institutional resources. We plan to recruit matriculating classes of 8 students who are expected to graduate in 8 years or less. The Medical Scientist Training Program at The University of Chicago Pritzker School of Medicine is in its 42nd year of uninterrupted funding and a superb training record of academic physicians in leadership positions (including current and former MSTP directorships at UCSF, Stanford, Harvard and Emory). It has graduated 227 students who have published over 2000 papers. Currently 76 individuals are enrolled in the program including 9% URM (up from 6% at our last renewal application) and 32% women. In the current cycle we have graduated or expect to graduate 44 students from the Program. Thirty-three students have entered. Continuing in the tradition of its graduates, our current MSTP students have published extensively in top journals such as Nature, Science, Cell, Immunity, Journal of Biological Chemistry, and others. In this proposal we provide compelling and detailed evidence on the superb quality of our students and the rigorous training environment at The University of Chicago which is uniquely configured to support interdisciplinary programs such as the MSTP. RELEVANCE: The University of Chicago Medical Scientist Training Program is designed for students who wish to pursue broad careers in research relevant to human health and disease. Overall, the MSTP seeks to fulfill a national need for individuals who will apply clinical and research experience to biomedical investigation and will catalyze the application of multidisciplinary approaches to solve the most pressing problems in medical science.